1. Field of the Invention
The present invention relates to a reinforcing bar binding device and more particularly to a portable reinforcing bar binding device used in reinforced concrete casting sites for winding a binding steel wire around column reinforcements, beam reinforcements, threaded dowel reinforcements or wall reinforcements at their intersections.
2. Prior Art
In constructing reinforced concrete structures such as buildings and bridge piers, various binding tools or devices including hookers and Hotchkiss type reinforcing bar binding devices for winding a binding steel wire around column reinforcements, beam reinforcements, threaded dowel reinforcements, wall reinforcements or other reinforcing bars at their intesections. For example, in the case of using a hooker, an annealed steel wire is folded double and wound around reinforcing bars at their intersection to form a loop of steel wire which is then hooked by the hooker and twisted to thereby bind the reinforcing bars at their intersection.
When reinforcing bars are to be bound at their intersection by a manual binding tool, for example, a hooker, as described above, all operations from the double-folding of steel wire to the twisting of wire subsequent to winding are performed through the operator's experience and sixth sense; thus, when there are differences in the hardness and thickness of steel wires, it is almost impossible in practice to expect to maintain at a fixed level the binding strength at intersections, resulting in adverse effects on the strength and dimensional accuracy of reinforced concrete structures. Further, reinforced concrete casting operations using such manual binding tool are generally low in operating efficiency, with the result that the saving of construction cost is limited. Further, the Hotchkiss type reinforcing bar binding device has a drawback in practice that the binding strength on reinforcing bars is insufficient because of structural limitations, and the cost of the device greatly limits the application of the device.